Mobile units having an antenna, such as a two-way radio or a vehicle mounted radio, generally include an antenna mounting fixture to support an antenna. As an example, a mobile unit 100 is shown in FIG. 1. The mobile unit 100 can include an antenna 170, an antenna mounting fixture 120, a printed circuit board (PCB) 180, and a mechanical housing 190. The antenna 170 is a detachable antenna external to the mobile unit 100 that connects to the internal antenna mounting fixture 120. The antenna mounting fixture 120 couples signals received by the antenna 170 to radio frequency (RF) components on the PCB 180 within the mobile unit 100. The internal mounting fixture 120 is fixed to the PCB 180 and aligns with an opening of the housing 190 to receive the external antenna 170. The antenna mounting fixture 120 is also precisely positioned on the PCB 180 to correctly receive the antenna 170 through the opening. The antenna mounting fixture 120 must be accurately coupled to both the PCB 180 and the housing 190 to properly receive the antenna 170. Any deviation in the placement of the antenna mounting fixture 120 on the PCB 180, or the attachment of the PCB 180 to the housing 190 can prevent the external antenna 170 from being correctly received.
The conventional antenna mounting fixture 120 of the prior art is shown in FIG. 2. The antenna mounting fixture 120 is a composite assembly that rigidly attaches to the printed circuit board (PCB) 180 within the mobile unit. The antenna mounting fixture 120 includes a RF connector 230, a flange 250, and a support base 240. The support base 240 physically attaches to the PCB 180 to receive the RF antenna signals. The support base 240 can be soldered to the PCB 180 during assembly to provide electrical coupling of the antenna 170 to the RF components on the PCB 180. A pair of support pins 241 provide a secure attachment to the PCB 180. A first ground pin 242 and a second ground pin 244 coupled through the RF connector 130 to the antenna 170 also serve as support pins for rigidly connecting the support base 240 to the PCB 180. A fixed signal pin 246 is also coupled through the RF connector 130 to the antenna 170. The fixed pin 246 is soldered to the PCB board 180 to provide the RF signal to the RF components on the PCB. Notably, the first ground pin 242, the second ground pin 244, and the fixed signal pin 246 are at fixed locations on the support base 240. The rigid attachment of the support base 240 to the PCB limits an allowable tolerance of connection points to the PCB board. In particular, the location of the connections on the PCB must align sufficiently with the pins (242, 244, and 246) on the support base 240. Moreover, if the support base 240 is not properly placed on the PCB 180, or the PCB 180 is not adequately positioned in the housing 190, then the antennae 170 may not properly attach to the antenna mounting fixture 120 thereby leading to mechanical strain. In such regard, the antenna mounting fixture 120, which is rigidly attached to the PCB 180, may generate stress on the PCB 180 which can lead to breaking or electrical failure if the antenna 170 is improperly mounted.
Tolerances for the ground and signal pins of the support base 240 are accounted for in the design of the PCB 180 to ensure electrical coupling compliance. Large tolerances of the connection point locations on the PCB are required to compensate for any deviations in the pin locations of the support base 240. Consequently, larger traces must generally be designed into the PCB 180 to anticipate pin location deviations in the support base 240. The larger traces allow for the pins (242,244,246) of the support base 240 to be aligned with the corresponding connectors on the PCB over a larger area. As a result, the PCB boards are generally larger in size to accommodate for the larger tolerances. The large tolerances do not provide for efficient packaging or miniaturization. A need therefore exists for a robust antenna mounting fixture that requires less design tolerance.